1. Technical Field
The technology presented herein relates to an image processing using the orthographic projection method, and more specifically, relates to a parallax scrolling control and a scaling process conducted in an image processing using the orthographic projection method.
2. Description of the Background Art
Conventionally, as a method to express depth perception and a sense of perspective, a display method that conducts so called parallax scrolling has been known (for example, Japanese Laid-Open Patent Publication No. H09-6296). This display method is a method that envisions a two-dimensional image processing. On the other hand, game systems that conduct a three-dimension displaying process for a game screen are commonly used in recent years. Generally, in such game systems, character objects and various structures, which are respectively arranged in predetermined coordinate positions, are used as display objects in a game field set in a virtual three-dimensional space; and a viewpoint position and a gazing point are set so as to define a display range of the game screen, and a game image which is taken using a perspective projection method is displayed.
The technology disclosed in the above described Japanese Laid-Open Patent Publication No. H09-6296 is a process that envisions processing in two dimensions, and is not a technology that envisions a virtual three-dimensional space. On the other hand, when the perspective projection method described above is used, depth perception can be expressed without conducting a parallax scrolling. Therefore, a technology that anticipates and envisions a parallax scrolling using the so-called orthographic projection method has not been known. In particular, a technology that anticipates and envisions an image processing which conducts a parallax scrolling control and additionally conducts scaling up or down of a screen using the orthographic projection method has not been known.